April 2008
Eddie Feltes— 7 May 2008 — in California Condor Restoration    ShareApril 2008 has had our crew on their toes and ready for anything. This eager and willing attitude stems from the behavior of the wild birds and the excitement of what may lie ahead as we manage an ever increasing and an always intriguing population of condors. In the past month we have trapped and tagged for the first time our two wild-fledged birds, trapped almost our whole population for blood lead testing and transmitter changes in just two weeks, tracked and recovered a condor with a severe wing injury, and monitored four (but most likely five) active nests across the condors expansive range here in Northern Arizona. To say it has been a busy month is an understatement, but this kind of busy is what our crew lives for!

In early April we were closely monitoring our two wild-fledged chicks in hopes of trapping and tagging them before they got into a pattern of consistent foraging away from the release site, and away from our trapping capabilities. Once both birds made a habit of routinely feeding amongst the rest of the birds, and seemed comfortable doing so, we decided to bait and set our trap for tagging, testing of blood lead, and attaching transmitters to allow daily tracking of the birds travel.

On 20-21 April we were able to do just that. We started by catching young Condor 441 first. This young condor fledged from a very isolated cave in a secluded canyon west of the Kaibab Plateau in the Grand Canyon, went six months undetected by our crew, and then became routinely visible again as the bird grew independent from the parent condors, female Condor 210 and male Condor 134, and began traveling and foraging with other birds in the population. This early independence is not very common, but has happened, as the adults usually tend to the young bird for another year after fledging at the age of six months. And as uncharacteristic as it may be—both wild-fledglings exhibited this behavior at the same time this year.

The other young bird, Condor 459, has been observed still feeding from male Condor 114, but has also been feeding independently more often at our release site with a large number of free-flying birds. So both birds were trapped, and after a field test of lead concentration in the blood came back at a releasable level, both birds were released immediately and have been doing great since. Condor 441 has even been documented traveling up to Southwestern Utah with a handful of other condors in the Kolob region, and returning back to the release site.

As a standard practice in our management of the flock, we always like to wait several weeks after releasing new birds, to allow them to gain confidence in feeding at the proffered carcasses that we put out and allow the birds to get comfortable roosting in safe locations in the cliffs before we do any trapping that may potentially break them of these desired habits. So once the four birds that were released 15 March settled in to this routine, we decided it to be a good time to carry out our bi-annual trapping of the entire free-flying population for transmitter placement and blood lead testing.

During our routine trapping, we noticed a break in the pattern of a few birds that were ranging to an uncommon location day after day, and returning with a visible crop full of food. Knowing the location and the unlikelihood of there being any natural carcasses of ungulates in the area, we put these birds on high alert and scoured the area they were covering with the feeling that something out of the ordinary was going on.

The tracking of female Condor 302 led veteran crewmember Eric Weis to the carcass of a domestic dog that once collected and examined at our treatment facility, revealed several metallic fragments in the carcass remains—indicating that it had been shot. So having the trap set we just had to monitor these five condors and wait for them to return to the trapping site. Once we trapped and tested all five, we were able to justify our concerns of being alarmed at this odd change in pattern of the birds. Two of the five birds, Condors 302 and 366, were tested in the field and showed high levels of lead exposure, and were later x-rayed with both birds showing fragments in their digestive tract. Currently both birds are in treatment for lead poisoning and are recovering well.

Another odd change in behavior was red-flagged by the mindful observation of crewmember Shaun Putz on 26 April. With a regular group of birds routinely ranging between the release site in the Vermilion Cliffs to Navajo Bridge in the Colorado River corridor, Shaun noticed one bird lagging behind as the other birds vacated the area. This was odd behavior for male Condor 250, because his dominance and leadership amongst this group had been regularly observed in the weeks prior.

After spending half of the day trying to get a visual on the bird’s location, which had not moved via the radio transmitter, from the canyon rim above, Shaun traveled downriver from Lee’s Ferry with Glen Canyon Park Rangers to try and find the bird from river level. With radio telemetry Shaun was able to track Condor 250 down to a boulder cave on the talus above the river. With cautious approach to not spook the bird off of a potential nesting situation, Shaun took a few pictures of the bird and had to vacate back upriver because of time constraints and safety in ensuring the boat would make it back upriver against the strong rapids of the Colorado.

Upon looking over the pictures that Shaun took, we decided that the bird appeared to be injured and was helplessly backed into the cave, unable to fly with his right wing hanging. So early the next morning Shaun and I headed back downriver with Park Rangers to try and net the bird for closer diagnosis of the situation. We were able to do so, and examine the bird in our treatment facility on site. Once we took a radiograph of the injured wing, we were able to see a dislocation in the carpal joint in the condor’s wing and immediately fly the bird, with assistance from the Arizona Game and Fish Department, to the Phoenix Zoo where an experienced staff is currently treating the injured condor.

To date we have reason to believe, based on behavior at the nest cave sites, that two pairs are tending to the successful hatching of condor nestlings deep in the Grand Canyon. With an inability to be able to see directly into either cave, we must dedicate vigilant attention to the behavior of the nesting pairs right around the suspected hatch dates, as certain behavioral changes usually indicate a hatching of the egg. And with hatch dates of 15 April for Condors 127 and 123 and 21 April for Condors 133 and 187, all seems to be going well so far.

During this close monitoring, we also have reason to believe that a third egg is currently being incubated by an unsuspected pair also deep in the Grand Canyon, that of female Condor 234 and female Condor 280! Both birds have been observed displaying to each other, and are now making regular nest switches that always leave one bird sedentary for a few days until the other bird returns, and then the pattern switches- indicating the switching of egg incubation duties. Suspicions of this behavior have been further solidified by placing a very reliable GPS transmitter on female Condor 280 that gives a fixed GPS location of the bird’s travels every hour of daylight. And with this particular unit functioning very reliably (like clock-work), I thought it to be odd that once the bird traveled to the possible nesting location and switched out Condor 234, the unit stopped transmitting—indicating being inside a cave location identical to the behavior of the other breeding condors that are wearing GPS transmitters. With a handful of available, breeding-aged male condors in the area, a situation like this is always possible, unlikely, but as we are seeing, definitely possible. At the time of writing we have a crewmember backpacking down in the canyon, searching for a cave location, to confirm our suspicions of this odd pair.

Back near the release site in the Vermilion Cliffs, the breeding pair of Condors 195 and 158 have been incubating strongly, and are due to hatch on 10 May, and the nest failure of experienced pair Condors 126 and 114 that was thwarted by the breaking of their egg, has been re-established as the pair has recycled and laid again, starting incubation on 22 April.

Check back with next month’s NFTF to get updates on the hopeful returns of our treated condors, as well as all the other happenings of this dynamic species recovery. Until next time. . .

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